JPH042035A - Discharge lamp device - Google Patents

Abstract

PURPOSE:To prevent ultraviolet rays generated along with light emission of a discharge lamp from going out of an ultraviolet ray shielding globe certainly by enclosing the lamp with this globe. CONSTITUTION:A discharge lamp device 10 is chiefly composed of a discharge lamp 12, lead supports 22, 24 supporting the lamp 12 while installed projectively at an insulative base 20, and an ultraviolet ray shielding globe 30A surrounding the lamp 12. This globe 30A formed in a cylinder having a spherical front end and a rear end which is left open is fixed to the insulative base 20 in the condition that the supports 22, 24 and discharge lamp 12 are enclosed totally. The whole peripheral surfaces of a tip-blocked glass tube of this globe 30A are coated with an ultraviolet ray shielding film, which absorbs ultraviolet rays generated along with light emission of the discharge lamp to permit only visible beams to go out of the globe 30A.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a discharge lamp device, and more particularly to a discharge lamp device equipped with a glass tube for shielding ultraviolet rays surrounding the discharge lamp.

[Prior art and inventions to be solved! [8] In recent years, discharge lamps have attracted attention in the automotive lamp industry because they have good luminous efficiency and color rendering properties, and have a long lifespan. However, for example, a metal halide lamp, which is a type of discharge lamp, generates a large amount of ultraviolet light as well as visible light when emitting light due to the sealing gas (mercury, iodide, Xe gas) in the discharge space. and wavelength range 240-290
Ultraviolet rays in the wavelength range of 29 nm destroy protein molecules.
Ultraviolet light between 0 and 320 nm causes skin cancer.
It is said that ultraviolet rays in the wavelength range of 360 to 370 nm can destroy resin materials. As described above, since the light emitted from the discharge lamp contains ultraviolet rays that are harmful to the human body, there is a problem in that exposure to the irradiation over a long period of time is not good for health, and the resin members around the discharge lamp deteriorate quickly.

As a conventional technology for cutting ultraviolet rays, Japanese Patent Publication No. 6
No. 0-138845, which has a structure in which a glass tube 4 for cutting ultraviolet rays is arranged around a discharge lamp 2, as shown in FIG. Another prior art example is Japanese Patent Publication No. 62-53904, which, as shown in FIG. 12, has a structure in which a discharge lamp 2 is sealed inside a glass tube 6 for cutting off ultraviolet rays.

[Problem to be solved by the invention]

However, in the first prior art described above, the lead stay 5
Although it has a simple structure in which the glass tube 4 is supported through the
Since the glass tube 4 has the opening 4a, there is a problem in ensuring reliable shielding of ultraviolet rays.

Furthermore, in the second prior art, in order to reduce the adverse effects of the temperature and pressure inside the sealed glass tube 6 on the lighting of the discharge lamp 2, the glass tube 6 is filled with an inert gas such as N2 gas, or a vacuum is used. However, there are problems in that equipment for this is required and manufacturing is also troublesome.

The present invention has been made in view of the problems of the prior art,
The purpose is to provide a discharge lamp device with a simple structure that can reliably block ultraviolet rays.

[Means to solve the problem]

In order to achieve the above object, in the discharge lamp device according to the present invention, the discharge lamp is supported by a pair of lead supports protruding forward from the M-edge base, and a UV shielding glove is provided around the discharge lamp. In the discharge lamp device, the globe has a structure in which an ultraviolet shielding film is formed on the inside and/or outside of a glass tube with a closed end, and a rear end opening of the globe is closed on the insulating base. The glove is held in a fixed position so that the lead support and discharge lamp that protrude forward of the insulating base are completely covered by the glove.

[Effect]

The rear end opening of the globe is fixedly held on an insulating base, and the area around the discharge lamp is sealed by a UV shielding glove, and the UV shielding film formed on the globe protects against the UV rays generated when the discharge lamp emits light. Reliably blocks radiation from exiting the glove.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

1 to 3 show a first embodiment of the present invention,
FIG. 1 is a partially cutaway side view of the discharge lamp device;
Figure 2 is a cross-sectional view of the lamp device (the line shown in Figure 1 -
FIG. 3 is a perspective view of the main parts of the lamp device.

In these figures, the discharge lamp device 10 includes a discharge lamp 12 that is a light emitting part, lead supports 22 and 24 that protrude from an insulating base 20 and support the discharge lamp 12, and a lead support 22 and 24 that surrounds the discharge lamp 12 and is used for shielding ultraviolet rays. glove 3
It is mainly composed of 0A.

The discharge lamp 12 has an ellipsoid-shaped sealed glass bulb 13 formed by pinching both ends of a quartz glass tube to form a discharge space.
It has a structure in which pinch parts 14, 14 are formed at both ends of the glass bulb 13, and a starting rare gas, mercury, and metal halide are sealed inside the glass bulb 13. Further, a discharge electrode 15.15 made of tungsten is disposed facing each other in the discharge space, and the discharge electrode 15.15 is connected to a molybdenum foil 16 sealed to the pinch part 14. A lead wire 18° 18 connected to a molybdenum foil 16 is led out from. The lead wires 18, 18 are attached to a metal support 19 at 1/P, a pair of long and short lead supports 22° 24 that are insert-molded in the marginal base 20 and protrude in front of the base.
a, 19b, and the discharge lamp 12 is connected to the lead support 22.24 via the lead wire 18.18.
The structure is supported at both ends. Insulating base 20
is made of, for example, a synthetic resin material, and has a disk-shaped base 20a.
and a disk-shaped protrusion 20b that is slightly thicker and smaller in diameter than the base 20a are integrally formed.

Note that the reference numeral 17 is an insulating cylindrical body made of ceramic and fitted to the lead stay 22 for preventing discharge.

Reference numeral 30A is a cylindrical UV-shielding glove with a spherical front end and an open rear end.

Lead support 22.2 fixed to insulating base 2o
4 and the discharge lamp 12 are completely covered. The rear end opening of the glove 30A is sized to fit on the outer periphery of the protrusion 20b of the base 20, and furthermore, a metal plate 40 provided on the base 20 can be press-fitted into the outer periphery of the rear end opening by caulking. A recess 32 is formed. A portion 41 of the metal plate 40 is integrally formed into the base 20 by insert molding, and a rectangular portion 42 of the metal plate 40 protrudes from the front surface of the base.
A gap corresponding to the thickness of the globe 30A is formed between the groove b and the rectangular portion 42. The metal plates 40 are provided at four equal positions in the circumferential direction, and in order to fix the glove 30A to the base 20, first the opening of the glove 30A is placed on the metal plate 40.
so that it is just sandwiched between the base protrusions 20b.

The rear end of the glove is fitted into the base protrusion 20b, and the metal plate 40 and the recess 32 are made to correspond.

Next, the rectangular portion 42 of the metal plate 40 is pushed radially inward from the outside using a metal rod 33 (see FIG. 2), which is a jig, to partially deform the rectangular portion 42 and push it into the recess 32. Press fit and fix the glove rear end opening to the base 20 by caulking. Reference numeral 43 in FIGS. 1 and 2 indicates a caulking portion. As a result, the rear end opening of the globe is kept closed by the base protrusion 20b, and the discharge lamp 12 is completely covered by the globe 30A and the base 20.

The space around the discharge lamp 12 is sealed by the ultraviolet ray shielding glove 30A, and the ultraviolet rays emitted from the discharge lamp 12 are reliably cut by the ultraviolet ray shielding glove 30A.

The ultraviolet ray shielding globe 30A has a structure in which the entire outer peripheral surface of a glass tube with a closed end is coated with an ultraviolet ray shielding film 34A made of ZnO, and the ultraviolet ray shielding film 34A covering the discharge lamp 12 is generated at the same time as the discharge lamp emits light. It absorbs ultraviolet rays and only visible light from which the ultraviolet rays have been cut is emitted to the outside of the glove 30A. To form the ultraviolet shielding film 34A, fine particles of ZnO are dispersed in an inorganic binder (concentration 20 to 30%), and this is applied to the glove surface by an appropriate method such as dipping, spraying, or vapor deposition. In order to set the transmittance of ultraviolet rays shorter than 370 nm to O, a film thickness of 1°6 μm or more is required, and from the viewpoint of preventing peeling, it is desirable to have a film thickness of 5 μm or less. In addition, the wavelength range of ultraviolet rays that can be cut varies depending on the temperature around the glove (when the temperature gets higher, the wavelength range that is cut shifts to the longer wavelength side), so the film thickness must be such that it can at least block ultraviolet rays in the wavelength range of 370 to 380 nm or less. adjust. Note that the film thickness can be adjusted by changing the dipping pulling speed or by changing the number of times of coating.

In the above embodiment, the ultraviolet shielding film 34A is made of ZnO.
However, the film may be made of a compound having an ultraviolet absorbing effect such as TiO2, Cab, Fez○3, etc., although the ultraviolet absorbing effect is inferior to that of Zn○.

Further, in the embodiment described above, the glove is attached to the insulating base 20.
The structure is such that the rectangular portion 42 of the metal plate 4o is caulked as a means of fixing the metal plate 4o.
- Other mechanical fixing means as shown in FIGS. 6(a) and 6(b), fixing means using adhesive, etc. can be considered. Figure 4(a).

In (b), a metal band 44 is protruded around the protrusion 20b of the insulating base 20, the opening end of the glove is fitted between the metal hand 44 and the protrusion 2Ob, and the metal band 44 is caulked to form the glove 30A. It is a structure that fixes the

Figures 5(a) and (b) show iI4! A pair of metal bands 4 facing each other close to the protrusion 20b of the A-edge base 2o
6.46 is provided by insert molding, and both bands 46.
46 surrounds the rear end opening of the glove and fixes the ultraviolet shielding glove 30B. Furthermore, code 35
is a metal band 4 protruding from the outer periphery of the glove opening end.
The glove 30B has the same structure as the glove 30A except that this collar 35 is formed.

FIGS. 6(a) and 6(b) show the protrusion 20 of the insulating base 2o.
In this structure, a pair of metal plates 48, 48 are provided by insert molding close to b, and both metal plates are engaged with the engagement hole 37 on the glove side and deformed to fix the ultraviolet shielding glove 30C.

This glove 30C is also 1. It has the same structure as the glove 30A except that a collar for forming the engagement hole 37 is formed. A detailed explanation of the glove fixing means shown in FIGS. 4 to 6 and other glove fixing means is actually disclosed in the specification of Application No. 2-12780, so the explanation thereof will be omitted.

FIG. 7 shows the main part of a second embodiment of the invention, showing an enlarged cross section of a globe arranged around a discharge lamp.

In this figure, the reference numeral 30D is a glove for shielding ultraviolet rays, which is formed on the outer circumferential surface of the glass tube and has an ultraviolet ray shielding film 3'4B.
It is constituted by a dielectric multilayer film made of a compound having an ultraviolet absorbing effect and having a different refractive index, such as F r T a 20 s. In the figure, T i 02 layer 34a
The ultraviolet shielding film 34B is composed of a dielectric multilayer film in which Si, 0□ layers 34b are alternately laminated, and ultraviolet rays in the wavelength range of 360 nm or less are absorbed by the Si02 layer and 1102 layer, respectively, and the ultraviolet light in the wavelength range of 360 to 380 nm The ultraviolet rays are canceled out by the reflected light at the interface between each dielectric layer.

Also, a multilayer film with a Ta205 layer instead of the Ti02 layer.

That is, it may be a structure in which T a 205 layers and 5i02 layers are alternately laminated, and in this case, the wavelength range 300
Ultraviolet rays of nm or less are absorbed by each dielectric layer, and ultraviolet rays in a wavelength range of 300 to 380 nm are canceled out by the reflected light at the interface between each dielectric layer. Furthermore, TiO
It may be a multilayer film structure in which □ layers and MgF layers are alternately laminated. That is, each dielectric layer (for example, 34a, 34b)
The film thickness d is set to d = n / 4λ (λ: the wavelength to be canceled, n: the refractive index of the dielectric material), and by setting this film thickness d to an appropriate value, the boundaries between each dielectric layer can be The phase of the reflected light on the surface is reversed with respect to the phase of the incident light, and this reflected light acts to cancel out the ultraviolet light having the wavelength λ.

Further, the thickness of the dielectric layer increases as the distance from the discharge space, which is one light emitting part, increases, thereby preventing changes in the wavelength range of ultraviolet rays to be cut. That is, the wavelength range of ultraviolet light absorbed by the ultraviolet shielding film shifts toward shorter wavelengths in proportion to the angle of incidence of light on the film. Therefore, if the thickness t of the ultraviolet shielding film (dielectric multilayer film) 34B is made uniform in the longitudinal direction of the glove, there is a problem that the ultraviolet absorption effect at the front and rear ends of the glove is poor. More specifically, compared to the central region of the globe, which faces the glass bulb 13 almost directly and where the angle of incidence of light on the ultraviolet shielding film (dielectric multilayer film) is approximately O, the more the front and rear ends of the globe, the more the ultraviolet rays The incident angle θ of light on the shielding film (dielectric multilayer film) is large, and the ultraviolet ray cutting effect is inferior (the ultraviolet wavelength range to be cut shifts to the shorter wavelength side). Therefore, as shown in Figure 8,
The film thickness of each dielectric layer 34a, 34b is made thicker toward the front and rear ends of the glove (thickness t of the ultraviolet shielding film 34B), so that the wavelength range of ultraviolet rays that is cut at any position of the globe 30B is approximately the same. It has been adjusted to be.

Note that in the two embodiments described above, the ultraviolet shielding film 34A,
Although the structure in which 34B is formed on the outside of the glove has been described, the ultraviolet shielding film 34A.

34B may be formed on the inside of the glove, or may be formed on both the outside and inside.

In addition, when the discharge lamp device according to the present invention is used as a light source for an automobile headlamp, as shown at 30E in FIG. It is also possible to form a light-shielding coated portion 36 called a light-shielding coated portion 36, and to form an ultraviolet shielding film 34A in the glass tube region excluding this light-shielding coated portion 36.

Furthermore, as shown at 3oF in FIG.

A globe structure may be used in which an ultraviolet shielding film 34A is formed on the inner and outer circumferential surfaces of the glass tube, and a shade 38 that blocks direct light is integrally attached to the opening on the front end side of the glass tube.

〔Effect of the invention〕

As is clear from the above description, the discharge lamp device according to the present invention has a simple structure in which a UV shielding glove is fixedly held on an insulating base, but the glove has an insulating rear end opening. The discharge lamp is held closed by the base, and the area around the discharge lamp is sealed by a UV-shielding glove, and the UV-shielding film formed on the globe ensures that the UV rays generated when the discharge lamp emits light do not exit the globe. Obstruct.

Furthermore, when the discharge lamp device according to the present invention is used as a light source for an automobile headlamp, since the amount of ultraviolet radiation is small, it becomes possible to use a front lens made of synthetic resin, which could not be used conventionally.

[Brief explanation of drawings]

FIG. 1 is a side view showing a part of a discharge lamp device according to a first embodiment of the present invention in cross section, and FIG. 2 is a cross-sectional view of the same lamp device (along the line 3 is a perspective view of the main parts of the lamp device, and FIGS. 4(a), (b) to 6(a), (b) are perspective views and sectional views of various globe fixing means. , FIG. 7 is an enlarged longitudinal cross-sectional view of a UV-shielding glove which is a main part of the second embodiment of the present invention, FIG. 8 is a cross-sectional view illustrating means for adjusting the thickness of the UV-shielding film, and FIGS. FIG. 10 is a longitudinal sectional view of an ultraviolet shielding glove which is a main part of another embodiment of the present invention, and FIGS. 11 and 12 are perspective views of the prior art. 1o...discharge lamp device. 12...Discharge lamp, 20...Insulating base, 20b...Protrusion part which is a part of the insulating base into which the glove rear end opening is fitted, 22.24...Lead support, 30A ~30F...Gloves for blocking ultraviolet rays, 34A
...UV shielding film, 34B...Dielectric multilayer film which is a UV shielding film, 40.
48...Metal plate that is a glove fixing member, 44.46
...A metal band that is a glove fixing member. Patent applicant Koito Seisakusho Co., Ltd. Figure (0) \ Figure (b) Figure (0) \ Guan Yin (b) Figure 1 Figure 12 Figure Figure Figure Figure Figure

Claims (1)

[Claims] (1) In a discharge lamp device in which a discharge lamp is supported by a pair of lead supports protruding forward from an insulating base, and a globe for shielding ultraviolet rays is arranged around the discharge lamp, the globe has a block at the tip. The glove has a structure in which an ultraviolet shielding film is formed on the inside and/or outside of the glass tube, and the rear end opening of the glove is fixedly held in a closed state by the insulating base and protrudes in front of the insulating base. A discharge lamp device characterized in that a lead support and a discharge lamp are completely covered by a glove.